The invention relates to a barrier apparatus for resisting passage of harmful gases from a space through a substantially vertical opening having a top, a bottom and lateral sides, the barrier apparatus comprising a suction arrangement for sucking gases and blowing arrangement for creating a flow of a medium.
A barrier apparatus as described above is known for example from the International Patent Publication WO 93/10861. This reference discloses spray heads mounted above a doorway and arranged to produce a fog-like curtain of water. The spray heads operate at a high pressure, i.e. over 50 bar, and they produce in their immediate surroundings a high negative pressure that sucks smoke gases into the water spray. When the smoke gases are mixed with the spray, which preferably comprises a huge number of small droplets of water, the particles in the smoke gases are absorbed into the spray, thus mixing with the water droplets and being purified. With this method the harmful effects of poisonous gases have been greatly reduced. Another advantage is that when spray heads are arranged in small spaces, such as ship cabins and hotel rooms, smoke gases can be prevented rather effectively from spreading outside the small spaces, for example to corridors and further to other spaces.
The barrier apparatus disclosed in WO 93/10861 has been found to be especially effective in preventing smoke from spreading from small rooms to other spaces. Due to the operation described above, the barrier apparatus are also used to extinguish a fire. However, the spray means are not particularly applicable for use in large spaces, i.e. when smoke should be effectively absorbed and purified in big spaces.
The invention also relates to a method of guiding and processing harmful gases, especially smoke gases produced in a fire, near a substantially vertical opening, especially a doorway, and in a space comprising the harmful gases, in which method a flow of medium is created in the immediate vicinity of the opening.
WO 93/10861 discloses a method for guiding and purifying smoke gases near a doorway. Smoke gases can be guided and purified effectively when the spray means are located in a rather small space, which is subjected  to a fire and should thus be purified of smoke gases. However, if the space that should be purified is large and there is no fire, the purification of smoke gases is not as effective as it should be.